package etc.spec.ytt.week09;

public class Test {
    public static void main(String[] args){
        double a=Math.PI;
        final double PI = 3.14159265358979323846;
        System.out.println("PT/5的正弦值:"+Math.sin(PI/5));
        System.out.println("1000的平方根:"+ Math.sqrt(1000));
        System.out.println("2的10次方:"+Math.exp(3));
        System.out.println("100.9向下取整:"+Math.floor(100.9));
        System.out.println("100.1向上取整:"+Math.ceil(100.1));
        System.out.println("100.4四舍五入取整："+Math.round(100.4));
        System.out.println("100.5的四舍五入取整:"+Math.round(100.5));
        String s="abcdefgHIJKLMN";
        StringBuffer str=new StringBuffer();
        str.insert(1,"M");
        System.out.println(str);
        str.insert(2,"N");
        System.out.println(str);
        str.deleteCharAt(10);
        System.out.println(str);
        str.replace(13,14,"NM");
        System.out.println(str);
    }

}
